package offer;

import java.util.Scanner;

/**
 * @author cyt
 * @create 2020-05-19 15:27
 */
public class T3 {

    /**
     * 学习下 string , string buffer
     *
     * @param args
     */
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        StringBuffer buffer = new StringBuffer("A B");
        int p1 = buffer.length() - 1;
        for (int i = 0; i <= p1; i++) {
            if (buffer.charAt(i) == ' ') {
                buffer.append("  ");
            }
        }
        int p2 = buffer.length() - 1;
        for (int i = p1; i >= 0; i--) {
            if (buffer.charAt(i) == ' ') {
                buffer.setCharAt(p2--, '0');
                buffer.setCharAt(p2--, '2');
                buffer.setCharAt(p2--, '%');
            } else {
                buffer.setCharAt(p2--, buffer.charAt(i));
            }
        }

        System.out.println(buffer.toString());
    }


}
